title: An aqueous pomegranate peel extract inhibits neutrophil myeloperoxidase in vitro and attenuates lung inflammation in mice.
abstract: Punica granatum peel aqueous extract (PGE) is widely used to treat disorders such as inflammation, ulcers and infections, but its pharmacological target is not known. In this study we investigated the effect of PGE on human neutrophil reactive oxygen species (ROS) production in vitro and on LPS-induced lung inflammation in vivo in mice. Neutrophils were isolated and ROS generation was measured by luminol-amplified chemiluminescence. Superoxide anion generation was detected by the cytochrome c reduction assay. H(2)O(2) was detected by DCFH fluorescence assay. Myeloperoxidase (MPO) activity was measured by the tetramethyl benzidine oxidation method. Lung inflammation was induced in mice by LPS instillation. PGE inhibited luminol-amplified chemiluminescence of resting neutrophils and N-formyl-methionyl-leucyl-phenylalanine (fMLF)- or phorbol myristate acetate (PMA)-stimulated neutrophils, in a concentration-dependent manner. PGE had no effect on superoxide anion generation, suggesting that it does not directly inhibit NADPH oxidase activity or activation pathways, or scavenge superoxide anions. PGE did not scavenge H(2)O(2) but directly inhibited myeloperoxidase activity in vitro. In vivo studies showed that PGE also attenuated LPS-induced lung inflammation in mice. So this study reveals that PGE inhibits neutrophil MPO activity and attenuates LPS-induced lung inflammation in mice. Inhibition of MPO activity by PGE could explain its anti-inflammatory action.
authors.affiliation: Faculté des Sciences de Gabès, Université de Gabès, Tunisia. Rafik.Bachoual@fsg.rnu.tn
authors.forename: Rafik
authors.initials: R
authors.lastname: Bachoual
authors.forename: Wifak
authors.initials: W
authors.lastname: Talmoudi
authors.forename: Tarek
authors.initials: T
authors.lastname: Boussetta
authors.forename: Françoise
authors.initials: F
authors.lastname: Braut
authors.forename: Jamel
authors.initials: J
authors.lastname: El-Benna
mesh_terms: D000818:Animals; D001992:Bronchoalveolar Lavage Fluid / Q000737:chemistry / Q000166:cytology; D002478:Cells, Cultured; D004195:Disease Models, Animal; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D005638:Fruit / Q000737:chemistry; D006801:Humans; D008168:Lung / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D029561:Lythraceae / Q000737:chemistry*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D009504:Neutrophils / Q000187:drug effects* / Q000378:metabolism; D009195:Peroxidase / Q000037:antagonists & inhibitors*; D010936:Plant Extracts / Q000494:pharmacology*; D011014:Pneumonia / Q000188:drug therapy* / Q000209:etiology / Q000473:pathology; D017382:Reactive Oxygen Species / Q000378:metabolism
chemical_list: D004791:Enzyme Inhibitors; D010936:Plant Extracts; D017382:Reactive Oxygen Species; D009195:Peroxidase